package chapter2;

import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

/**
 * Basic stream cipher example
 */
public class SimpleStreamExample {
	public static void main(String[] args) throws Exception {
		Security.addProvider(new BouncyCastleProvider());
		byte[] input = new byte[] { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, (byte) 0x88, (byte) 0x99,
				(byte) 0xaa, (byte) 0xbb, (byte) 0xcc, (byte) 0xdd, (byte) 0xee, (byte) 0xff };
		byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
				0x0d, 0x0e, 0x0f };

		SecretKeySpec key = new SecretKeySpec(keyBytes, "ARC4");

		Cipher cipher = Cipher.getInstance("ARC4", "BC");

		System.out.println("input text : " + Utils.toHex(input));

		// encryption pass

		byte[] cipherText = new byte[input.length];

		cipher.init(Cipher.ENCRYPT_MODE, key);

		int ctLength = cipher.update(input, 0, input.length, cipherText, 0);

		ctLength += cipher.doFinal(cipherText, ctLength);

		System.out.println("cipher text: " + Utils.toHex(cipherText) + " bytes: " + ctLength);

		// decryption pass

		byte[] plainText = new byte[ctLength];

		cipher.init(Cipher.DECRYPT_MODE, key);

		int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);

		ptLength += cipher.doFinal(plainText, ptLength);

		System.out.println("plain text : " + Utils.toHex(plainText) + " bytes: " + ptLength);
	}
}
